The advantages of the supplemental restraint system, in passenger vehicles, in combination with the use of seat belts have been well appreciated. Air bags are among the most successful safety devices in motor vehicles today. The use of air bags in modern vehicles is fast becoming an absolute standard.
Recently, however, a problem has arisen which presents both real and perceived hazards in the use of air bags. Air bags are primarily designed for the benefit of adult passengers. When children or infants are placed in the front passenger seat, deployment of an air bag can and has caused serious injury. Automobile manufacturers, realizing this hazard, have recommended that children and infants only ride in the rear passenger seats of an automobile.
According to the National Highway Transportation Safety Board, “smart” technology air bags should be in place starting with motor vehicles built in 1999. In short, “smart technology” air bags adjust air bag deployment to accommodate the specific weight considerations of the passenger who would be affected by its deployment. The result is that small passengers are less often injured by the deployment of airbags.
While air bags have been credited with saving thousands of lives, the tremendous force of air bag deployment has also caused many injuries. Air bags have been blamed for deaths of many children and adults in low-speed accidents that otherwise would have been non-fatal.
Placing infants and small individuals in the front passenger seat of automobiles has led to some serious, but avoidable, tragedies. Unfortunately these accidents have had a secondary effect in that the public is beginning to perceive air bags as inherently dangerous and has begun to believe that they should be selectively disabled, if installed at all. In light of the statistics, however, airbags have resulted in a net increase in lives saved. Therefore, measures short of disabling or not installing air bags are needed.
Inevitably, children will be placed in the front passenger seats of automobiles, whether due to ignorance of the hazards or simply due to the need to fit a certain number of passengers in a particular vehicle. Therefore, the solution lies in adapting the supplemental restraint system to adjust the deployment force of airbags to compensate for the presence of smaller passengers. It should also be noted that, while less likely, smaller adults also may be injured by the deployment of an air bag. The most obvious solution to the problem, which is popular with the public, is to provide for the disabling of the air bag. This solution has several problems. First, the operator may forget to disable the air bag when it should be disabled. Second, the operator may forget to enable the system when its protection is desired. Finally, entirely disabling the system deprives children and smaller passengers of the benefits of air bags.
In order to avoid some of the above problems, related prior art has incorporated measurement systems into the seats of some vehicles to gather information about the passenger and to operate the air bag in accordance with that information. These systems generally represent a simple “on” or “off” selection. For example, if a passenger is not located in the seat, or does not trigger certain secondary detectors, the restraint system may be disabled. If the detector properly senses a passenger in the vehicle, the air bag is simply enabled.
U.S. Pat. No. 4,806,713, issued Feb. 21, 1989, to Krug et al., which shows a seat contact switch for generating a “seat occupied” signal when an individual is sensed atop a seat. The Krug et al. device does not have the ability to measure the weight of the seated individual.
U.S. Pat. No. 5,071,160, issued Dec. 10, 1991, to White et al., provides the next iteration of this type of system. A weight sensor in the seat, in combination with movement detectors, determines if it is necessary to deploy an air bag. If an air bag is deployed, the weight sensor determines what level of protection is needed and a choice is made between deploying one or two canisters of propellant. Unlike the present invention, White's invention is incapable of an air bag response tailored to an individual passenger. White's system only is capable of a high or low power air bag deployment.
U.S. Pat. No. 5,161,820, issued Nov. 10, 1992, to Vollmer, describes a control unit for the intelligent triggering of the propellant charge for the air bag when a triggering event is detected. Vollmer's device provides a multiplicity of sensors located around a passenger seat so as to sense the presence or absence of a sitting, standing, or kneeling passenger. The Vollmer device is incapable of sensing the weight of passengers and deploying the air bag with force corresponding to a passengers weight.